In this chapter you will find what the spell does and how to cast the spell correctly. Let's begin. To start you NEED to mean it. As Bellatrix stated in the books you need to want to cause them pain, not just to get back at them. Or as Harry did in the book "The Order of the Pheonix" that he was just mad and didn't really want to cause her any pain. Now that you know that you should also know that like the killing curse, this spell/curse has no wand movements required, but you can if you desire. Now that you know how to use it you should know how to say it. It is said Crucio. Now to continue to the next part of this chapter, what it does. The spell or as most people call it curse but I'm just going to call it spell. This spell causes the victom pain like they've never known. It is great for enemies, just so you know. If someone casts the spell more a long time it cam drive the victom into insanity.